LMH6401 Evaluation Module (EVM) Overview

[MUSIC PLAYING] Hello, I'm Anthony Vaughan with Texas Instruments High-Speed Amplifier marketing team. Today, I will demonstrate the key features of TI's LMH6401 Evaluation Module, or EVM.
The LMH6401 is a 4.5 gigahertz, ultra-wideband, fully-differential digital variable-gain amplifier that's ideal for use in DC to radio frequency or intermediate frequency applications. LMH6401 is also an excellent driver for high-speed analog-to-digital converters, and a great choice for DC or AC coupled applications that require automatic gain control.
The LMH6401 evaluation module is designed to quickly and easily demonstrate the functionality and versatility of the amplifier across all gain settings. It comes ready to connect to power, a signal source, and test instruments through the use of onboard connectors. It also has a USB connection for a PC, and an easy-to-use graphical application that is used to control gain and power-down settings.
The EVM consists of a single small circuit board shown here. The top side of the board features at the LMH6401 amplifier, a mini-USB connector, two input-signal SMA connectors, two output-signal SMA connectors, a power-down SMA input, and a common-mode voltage input. It has a red connector for the VS+ positive amplifier supply, a yellow connector for the VSA- negative amplifier supply, a white bias connector, and three black ground connectors.
There is also a jumper on the top side of the board that can be used to power down the amplifier. The bottom side of the board features an IC that interfaces with a PC USB port and the SPI serial interface on the amplifier.
A common setup environment for the LMH6401 EVM is shown in the diagram. External bench equipment featured in this diagram include a PC, of 5-volt split power supply, a signal generator, and a spectrum analyzer. To get started with the basic setup of the board, first connect the power supply.
The board may be configured for either split-supply operation or for single-supply operation. For split-supply operation, connect the positive supply voltage to the red VA+ connector. Then connect the negative supply voltage to the yellow VS- connector, and the ground reference to one of the black ground connectors.
For single-supply operation, the VS- connector and the ground connector should be connected to ground. The output common mode voltage will default to mid supply if the VOCM connector is left floating. Regardless of the configuration, the inputs and outputs must be biased per the LMH6401 datasheet specifications for proper operation.
Once the supply connections have been made, input signals may be connected to the board. Differential input signals can be applied to the N+ and N- SMA connectors. The differential output of the amplifier is available on the OUT+ and OUT- SMA connectors on the board. SMA cables can be connected to these terminals to route the signal to test equipment or to another circuit board. Also ensure that the power-down jumper is removed from the board to ensure that the amplifier is an active mode.
The next step is to power up the amplifier power supply and plug in one end of the mini-USB cable into a PC USB port. Then plug the other end of the USB cable into the EVM board. After all connections have been made, the PC application can be launched by going to the Start menu and selecting Programs, Texas Instruments, LMH6401 EVM GUI. If the application is not already installed, it can be downloaded from the website shown below.
Once the application has started, several settings and parameters for the amplifier can be modified. These include the power down state of the amplifier, the gain setting of the amplifier, and the thermal shut down, thermal feedback gain, and frequency controls. Using the Low Level View tab, individual registers in the amplifier can be read and written to change the settings for the amplifier.
For more details about the PC application, board setup, and different configurations available, take a look at the full EVM user guide that can be downloaded from the link shown below. The user guide also contains complete board schematics and a parts list. You can also get additional information about the LMH6401 and order a kit from this website
In addition to the LMH6401, TI has a broad portfolio of other fully-differential amplifiers. To see the entire portfolio, check out ti.com/fda. I hope that you have found this overview useful. Thank you for watching.
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